In the 3GPP (3rd Generation Partnership Project) that is a standardization project, Evolved Universal Terrestrial Radio Access (hereinafter, referred to as EUTRA), which has realized fast communication by employing a flexible scheduling per predetermined frequency/time referred to as an OFDM (Orthogonal Frequency-Division Multiplexing) communication scheme or a resource block, is now under study. In EUTRA, a mobile station apparatus makes a radio resource request (a scheduling request), thereby requesting radio resource allocation information (uplink grant) indicative of the transmission permission of a physical uplink shared channel, for transmitting uplink data, from a base station apparatus. The radio resource request is made by using a physical uplink control channel or a physical random access channel individually allocated to the mobile station apparatus (the detailed description of each channel will be described later).
In the radio resource request using a physical uplink control channel, a certain time is consumed before data is transmitted. Therefore, Non Patent Literature 1 proposes a contention-based data transmission method, wherein to a mobile station apparatus in which an uplink transmission timing is already adjusted, a base station apparatus newly allocates an uplink radio resource common to mobile station apparatuses using an uplink grant, and a mobile station apparatus having data to be transmitted transmits the data by using the uplink radio resource common to mobile station apparatuses, thereby reducing a delay time required to transmit uplink data. The uplink radio resource in this case is particularly referred to as also a contention-based radio resource.
Moreover, in the 3GPP, the discussion on Advanced EUTRA realizing faster data transmission and having upward compatibility with EUTRA is started. As the technique in Advanced EUTRA, carrier aggregation is proposed. The carrier aggregation is a technique for improving the data rate by aggregating and using a plurality of different frequency bands (referred to as also component carriers). Furthermore, it is also proposed that a mobile station apparatus communicating with a base station apparatus by using the carrier aggregation has a plurality of uplink transmission timings (Timing Advance) for each frequency or for each component carrier (Non-Patent Document 2).